With the development of communication technologies, mobile data usage in consumer electronic products has significantly increased. In response to the large demand of bandwidth, communication supervisory bureaus in many countries have been releasing more and more spectrum and trying to increase the efficiency of usage of spectrum for broadband mobile service. For example, communication mechanisms such as Long Term Evolution in Unlicensed band (LTE-U) and Licensed Assisted Access (LAA) are proposed to expand available spectrum of current mobile communication by using unlicensed spectrum.
However, no matter under LTE-U or LAA, unlicensed spectrum is used to compensate for the shortage of downlink licensed spectrum. There is no effective solution for uplink data transmission for LTE-U or LAA currently.
Therefore, there is a need to propose communication methods and devices capable of using unlicensed spectrum to perform uplink transmission.